Percutaneous endoscopic gastrostomy (PEG) is a medical procedure for placing a feeding tube through the abdominal wall and into the stomach of a patient, aided by endoscopy. PEG tubes are placed in a vast array of age-groups and disease-states to allow nutrition, fluids and/or medications to be put directly into the stomach, when oral intake is inadequate or not possible.
There are several techniques for performing PEG. In general, the procedure includes placing an endoscope into the patient's mouth and advancing it along the esophagus into the stomach. The endoscope allows viewing the stomach lining to determine the correct insertion site of the PEG tube, where a small incision is made in the abdominal wall. The procedure further includes inserting a guidewire and advancing the tube over the guidewire through the patient's mouth, esophagus, stomach and out through the abdominal wall. The PEG tube typically contains a retention means, both external and internal, to secure the tube in place and minimize accidental retraction and/or dislodgement.
There are several types of PEG tubes of different sizes and internal retention mechanisms. Examples include PEG tubes with internal mushroom-like soft and flexible bumper or bolster, PEG tubes with semi-rigid internal bumper that prevents their removal by external traction, and balloon-retained tubes where a balloon at the end of the tube positioned inside the stomach is inflated after insertion. The insertion of PEG tubes with a flexible or semi-rigid internal bumper is typically performed such that the end of the tube that is not engaged with the bumper is entered first, through the patient's mouth, and advanced in a retrograde manner along the guidewire and out the incision made in the abdominal wall until the retention bumper touches the internal wall of the stomach. The tube is then further secured using an external bolster affixed at the skin level. A schematic illustration of advancing a PEG tube with internal bumper (B) along a patient's esophagus is shown in FIG. 1A. Illustration of a PEG tube secured to the abdominal wall of a patient (externally and internally) is shown in FIG. 1B. Balloon-retained tubes are usually used when a tract has already been established in the abdominal wall. Such tubes can be inserted through the tract in a deflated form, and inflated when inside the stomach to secure the tube in place.
PEG tubes should be replaced regularly, typically every few months. Removal of PEG tubes (either for the placement of a new tube or in cases where enteral feeding is no longer required) can be performed by different methods, depending, inter alia, on the tube design. For example, mushroom-retained tubes can be removed by external retraction. Upon pulling, the internal flexible bumper folds and slides out through the tube tract. This technique typically causes considerable pain to the patient, and may result in complications such as perforation and peritonitis. As another example, PEG tubes with rigid internal bumpers can be removed by repeat gastroscopy and retrieval of the internal PEG bumper by the oral route. As this method requires repeat endoscopy, it is considered more complicated and costly. Another known method of PEG tube removal is the “cut and push” method (described, for example, in Kejariwal et al. 2009, Nutr Clin Pract, 24: 281), This method is generally applicable for PEG tubes with a rigid internal bumper, and involves cutting the tube at skin level and allowing the internal bumper to be expelled naturally. The “cut and push” method has several drawbacks. For example, the passage of the tube remnants and bumper through the gastrointestinal (GI) tract may cause bowel obstruction and/or perforation. The remnant tube “tail” might restrict free maneuvering of the bumper in the bowel, which is essential for proper extraction. In addition, the method is not recommended for certain patient populations, such as patients with previous abdominal surgery, known GI stricture and known motility disorders. In some cases, the insertion of a new, fresh tube entails another endoscopy.
Balloon-retained tubes can be removed by deflating the balloon. Although simple to operate, such tubes are considered less durable and more prone to tube complications, such as accidental dislodgment (see, for example, Funaki et al. 2001, AJR, 177(2); 359-362), which can be very hazardous in the 14 days after the insertion prior to mature tract formation (see, for example, Marshall et al. 1994, J Clin Gastroenterol, 18(3):210-2).
U.S. Pat. No. 4,795,430 discloses a device for intubating an ostomy, formed by a percutaneous endoscopic technique including a multi-lumen tube, having at least a fluid delivery lumen and an inflation lumen. The tube includes a port near one end to dispose the inflation lumen to ambient air and an outlet at another end to convey fluid from within the fluid lumen into a patient. A retention member, preferably an inflatable cuff, is joined near the other end of the tube and is inflatable and deflatable through the inflation lumen.
U.S. Pat. No. 5,112,310 discloses a gastrostomy tube which includes an elongated flexible wire guide and an elongated sleeve having a tapered end portion, the guide and sleeve having lengths sufficient to extend from a location outside the abdominal wall of the patient through the patient's stomach and esophagus and out the patient's mouth. The gastrostomy tube has a retention device in the form of an inflatable balloon or expandable and retractable cage adjacent an end portion for retaining the tube within the patient's stomach.
U.S. Pat. No. 5,391,159 discloses a gastrostomy tube which is a flexible tube having on one inner end thereof an improved energy absorbent internal retaining member. The energy absorbing internal retaining member has a hollow body portion with two resiliently reversible physical forms or shapes, toroidal-like, and, goblet-like connected to a foreshortened hollow axial stem portion that is attached to or integrally made with the inward end of the flexible tube. The internal retaining member is made in the toroidal-like form. During intentional removal, when under pressure against the stomach mucosa, the internal retaining member snaps into the unrolled, goblet-like shape and pulls smoothly out through the stoma tract.
U.S. Pat. No. 6,039,714 discloses an improved ostomy fluid tube and method for its use comprising a collapsible retention bolster for securing the tube to the inner stomach wall and fascia. The retention means comprise several resilient leaf or petal-shaped flanges circumferentially arranged about the feeding tube at a distal point thereon. The otherwise flat, circumferentially arranged flanges possess notches or grooves which facilitate collapse or folding of the retention means for easier removal through an ostomy or other internal cavity.
EP 2258334 discloses an apparatus for direct gastric feeding via a gastrostomy tract formed in a patient. The apparatus includes a tube, an internal bolster, an external bolster, and a force-generating device. The force-generating device may include a pair of automatically adjustable spring members on the external bolster. The spring members are responsive to changes in the length of the gastrostomy tract.
WO 2007/114880 discloses a surgical tool useful in performing percutaneous endoscopic gastrostomy and other surgical procedures requiring formation of a stoma into a body lumen. Such a tool would contain a first and second cannulae concentrically nested within one another and secured together at a distal end. An actuator is provided for selectively engaging and disengaging a retention mechanism located on that portion of the tool positioned within the body lumen. A locking mechanism is also provided to be used in conjunction with the retention mechanism for securing the cannulae to one another enabling the cannulae to be severed, and the actuator to be disposed, until the locking mechanism is disengaged upon formation and healing of an artificial stoma.
US 2011/0313359 discloses a gastrostomy tube including a retention device includes an elongated hollow shaft having a proximal first end and a distal second end and at least one retention member extending from the distal second end of the shaft. The at least one retention member moves between a retracted orientation and an open orientation.
There still remains a need for improved enteral feeding systems containing tubes and retention means which are easy to operate, durable and cost effective. In addition, there is a need for improved tubes for other ostomy procedures.